Growth Plate Injuries

Growth plate (physeal) injuries are fractures through the physis, the cartilaginous plate that drives longitudinal bone growth in children.

The physis is weaker than the surrounding bone and ligaments, so a force that would sprain a ligament in an adult often fails through the growth plate in a child. These injuries are common, peak in adolescence and are more frequent in boys.

Most heal well, but a minority cause growth arrest, angular deformity or limb-length discrepancy. The Salter-Harris classification is the framework throughout.

The physis sits between the epiphysis (the bone end near the joint) and the metaphysis (the flared end of the shaft). Its hypertrophic zone, where cartilage cells enlarge before turning to bone, is the weakest layer and the usual plane of fracture.

The germinal layer is supplied from the epiphyseal side, so injuries that disrupt that supply or crush the physis can stop growth:

• •Partial arrest tethers part of the plate while the rest grows, giving a progressive angular deformity
• •Complete arrest shortens the bone

The physis closes at skeletal maturity, at an age that varies by site and sex.